What determines who is at fault in a car, truck, motorcycle, or bicycle accident?

Figuring out who is at fault in a traffic accident is a matter of deciding who was careless. And, for vehicle accidents, there is a set of official written rules telling people how they are supposed to drive and providing guidelines by which liability may be measured. These rules of the road are the traffic laws everyone must learn to pass the driver's license test. Complete rules are contained in each state's vehicle code, and they apply not only to automobiles but also to motorcycles, bicycles, and pedestrians.

Sometimes a violation of one of these traffic rules is obvious and was clearly the cause of an accident -- for example, when one driver runs a stop sign and crashes into another.

In other situations, whether or not there was a violation will be less obvious -- a common example is a crash that occurs when drivers both merge into a single lane of traffic. These cases may be governed by the law of negligence. A driver, pedestrian, or cyclist who is "negligent" (that is, behaved in a thoughtless or careless manner) will be found at least partially at fault for causing the accident.

To prove negligence, four elements must be met: (1) the driver is legally required to be reasonably careful in the particular situation (this one is a given since drivers must use caution at all times); (2) the driver (or pedestrian or cyclist) was not reasonably careful; and (3) the driver's conduct caused actual injury or damage to someone. (To learn more about the law of negligence and fault in traffic accident cases, see Nolo's articles Car Accidents Caused by Negligence and Car Accidents: Proving Fault.)

Can I be found liable if my car is rear-ended in a crash?

If someone hits you from behind, the accident is virtually always that driver's fault, regardless of the reason you stopped. A basic rule of the road requires that a driver be able to stop safely if a vehicle stops ahead of the driver. If the driver cannot stop, he is not driving as safely as the person in front of him.

The other surefire part of rear-end accident claims is that the vehicle damage proves how the accident happened. If the other car's front end and your car's rear end are both damaged, there can be no doubt that you were struck from the rear.

In some situations, both you and the car behind you will be hit when a third car runs into the car behind you and pushes it into the rear of your car. In that case, it is the driver of the third car who is at fault and against whose liability insurance you would file a claim. For a step-by-step guide to protecting your legal rights after an accident, see How to Win Your Personal Injury Claim by Joseph Matthews (Nolo).

Is a car making a left turn always at fault in an accident?

A car making a left turn is almost always liable to a car coming straight in the other direction. Exceptions to this near-automatic liability can occur if:

the car going straight was going too fast (this is usually difficult to prove)

the car going straight went through a red light, or

the left-turn car began its turn when it was safe but something unexpected happened which made it have to slow down or stop its turn.

Whatever the contributing factors, the law says the car making the left turn must wait until it can safely complete the turn before moving in front of oncoming traffic. Also, the location of the damage on the cars sometimes makes it difficult for the other driver to argue that the accident happened in some way other than during a left turn. So, if you have had an accident in which you ran into someone who was making a left turn in front of you, almost all other considerations of fault go out the window, and the other driver is nearly always liable.

What if one of the accident victims was also at fault?

If a victim's actions are at least partially to blame for a vehicle accident, compensation for that person's injuries or property damage may be limited or barred completely, depending on where the accident occurred. In states that use the comparative negligence system, if both parties to an accident are negligent, fault is allocated between the parties. This means that the victim will not be able to recover fully for injuries or damages, but may get partial compensation. In states that follow the contributory negligence system, if both the victim and driver are negligent, the victim is barred from any recovery at all. Because the results in a contributory negligence system can be harsh, few states use this system. To learn more about comparative and contributory negligence, see Nolo's article Car Accident Defenses: Contributory and Comparative Defenses.

If a motorcyclist isn't wearing a helmet, can they still recover for injuries caused by another driver?

Whether a helmetless motorcycle rider can recover for head and neck injuries depends on whether the state where the accident occurred requires the use of helmets. All but three states have some type of motorcycle helmet law. Some states require all motorcycle riders to wear helmets. Others require helmets only for those riders under a certain age. In states with a helmet law, if a helmetless rider sustains injuries in a vehicle accident, it will be extremely difficult to recover for head and neck injuries. However, the rider may be able to recover for other injuries. In states that don't require the use of a helmet, recovery for head and neck injuries may be slightly easier. However, the insurance company is likely to produce a barrage of evidence demonstrating that helmet use drastically reduces the incidence of head injuries, and that by not wearing a helmet, the motorcyclist was negligent. To learn more about helmet laws in different states -- and how those laws may affect recovery in accident cases -- see Nolo's article Motorcycle Helmet Laws & Recovery for Injuries.

If I am the victim of a trucking accident, who can I sue?

If you are the victim of a trucking accident, understanding who is responsible for your injuries can be complicated. There is often a web of players that could be liable, and figuring out who they are isn't always easy. Some of the people and companies who could be on the legal hook for a trucking accident include:

To make matters worse, the trucking, hauling, and leasing companies often argue among themselves over whose insurance will compensate the victim. Your best bet in most trucking accidents is to consult a lawyer who has experience with these types of cases and knows what to expect from the parties involved. To learn more about trucking accidents, see Nolo's article Trucking Accidents: Common Causes & Liability. You can also use Nolo's Lawyer Directory to find a trucking accident attorney in your area.

If a bike and car collide, who is at fault for the accident?

Bicycles are considered "vehicles" in almost every state's official traffic or vehicle code. This means that cyclists must follow the same rules of the road that apply to cars, trucks, and motorcycles. In an accident between a car and a bicycle, fault is determined by the general principals of negligence. Bicyclists will not normally get a break just because their "vehicle" is smaller and powered by human legs. For example, if a cyclist runs a red light and is hit by a car that entered the intersection legally, the cyclist will most likely be deemed negligent and be unable to recover for their injuries. To learn more about liability for accidents involving bicyclists and cars, see Nolo's article Bike Accidents: Collisions With Cars at Intersections.

What should I do if I'm involved in a traffic accident?

Take notes. The most important thing you can do is to document the entire situation by taking careful notes soon after your accident. This step can help make the entire claim process easier on you -- and increase your chances of receiving all the compensation to which you are entitled. Having notes to remind you of all the details of what happened, and what you went through, is far easier and far more accurate than relying on your memory.

Write things down as soon as you can: Begin with what you were doing and where you were going, the people you were with, the time, and the weather. Include every detail of what you saw, heard, and felt. Be sure to add anything you remember hearing anyone -- a person involved in the accident or a witness -- say about the accident.

Finally, make daily notes of the effects of your injuries. You may suffer pain, discomfort, anxiety, loss of sleep, or other problems which are not as visible or serious as another injury, but for which you should demand additional compensation. (To learn more about what kind of information to track and record, see Nolo's article Take Notes After an Accident or Injury.)